Surgical instrument with single drive input for two end effector mechanisms

ABSTRACT

Methods for treating tissue, and surgical assemblies and related methods are disclosed in which a single input is used to sequentially articulate two members. A medical device includes an input link movable through an input link range of motion, a jaw coupled with the input link, and a tissue manipulation member coupled to the input link and positioned to manipulate a tissue gripped by the jaw. The input link range of motion includes a first portion and a second portion. The input link within the first portion of the input link range of motion drives the jaw through a jaw range of motion. The input link within the second portion of the input link range of motion drives the tissue manipulation member through a tissue manipulation member range of motion.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a Continuation of U.S. Ser. No. 14/498,750 filedSep. 26, 2014 (Allowed); which is a Divisional of U.S. Ser. No.13/484,143 filed May 30, 2012 (now U.S. Pat. No. 8,870,912); whichclaims the benefit of U.S. Provisional Application No. 61/491,821 filedMay 31, 2011; the disclosures which are incorporated herein by referencein their entirety for all purposes.

BACKGROUND

Minimally invasive surgical techniques are aimed at reducing the amountof extraneous tissue that is damaged during diagnostic or surgicalprocedures, thereby reducing patient recovery time, discomfort, anddeleterious side effects. As a consequence, the average length of ahospital stay for standard surgery may be shortened significantly usingminimally invasive surgical techniques. Also, patient recovery times,patient discomfort, surgical side effects, and time away from work mayalso be reduced with minimally invasive surgery.

A common form of minimally invasive surgery is endoscopy, and a commonform of endoscopy is laparoscopy, which is minimally invasive inspectionand surgery inside the abdominal cavity. In standard laparoscopicsurgery, a patient's abdomen is insufflated with gas, and cannulasleeves are passed through small (approximately one-half inch or less)incisions to provide entry ports for laparoscopic instruments.

Laparoscopic surgical instruments generally include an endoscope (e.g.,laparoscope) for viewing the surgical field and tools for working at thesurgical site. The working tools are typically similar to those used inconventional (open) surgery, except that the working end or end effectorof each tool is separated from its handle by an extension tube (alsoknown as, e.g., an instrument shaft or a main shaft). The end effectorcan include, for example, a clamp, grasper, scissor, stapler, cauterytool, linear cutter, or needle holder.

To perform surgical procedures, the surgeon passes working tools throughcannula sleeves to an internal surgical site and manipulates them fromoutside the abdomen. The surgeon views the procedure from a monitor thatdisplays an image of the surgical site taken from the endoscope. Similarendoscopic techniques are employed in, for example, arthroscopy,retroperitoneoscopy, pelviscopy, nephroscopy, cystoscopy, cisternoscopy,sinoscopy, hysteroscopy, urethroscopy, and the like.

Minimally invasive telesurgical robotic systems are being developed toincrease a surgeon's dexterity when working on an internal surgicalsite, as well as to allow a surgeon to operate on a patient from aremote location (outside the sterile field). In a telesurgery system,the surgeon is often provided with an image of the surgical site at acontrol console. While viewing a three dimensional image of the surgicalsite on a suitable viewer or display, the surgeon performs the surgicalprocedures on the patient by manipulating master input or controldevices of the control console. Each of the master input devicescontrols the motion of a servo-mechanically actuated/articulatedsurgical instrument. During the surgical procedure, the telesurgicalsystem can provide mechanical actuation and control of a variety ofsurgical instruments or tools having end effectors that perform variousfunctions for the surgeon, for example, holding or driving a needle,grasping a blood vessel, dissecting tissue, or the like, in response tomanipulation of the master input devices.

Manipulation and control of these end effectors is a particularlybeneficial aspect of robotic surgical systems. For this reason, it isdesirable to provide surgical tools that include mechanisms that providethree degrees of rotational movement of an end effector to mimic thenatural action of a surgeon's wrist. Such mechanisms should beappropriately sized for use in a minimally invasive procedure andrelatively simple in design to reduce possible points of failure. Inaddition, such mechanisms should provide an adequate range of motion toallow the end effector to be manipulated in a wide variety of positions.

Non-robotic linear clamping, cutting and stapling devices have beenemployed in many different surgical procedures. For example, such adevice can be used to resect a cancerous or anomalous tissue from agastro-intestinal tract. Many known surgical devices, including knownlinear clamping, cutting and stapling devices, often have opposing jawsthat are used to manipulate patient tissue.

In many existing minimally invasive telesurgical robotic systems,manipulation of the surgical instruments is provided by a surgical robothaving a number of robotic arms. Each of the robotic arms has a numberof robotic joints and a mounting fixture for the attachment of asurgical instrument. Integrated in with at least one of the mountingfixtures are a number of drive couplers (e.g., rotary drive couplers)that drivingly interface with corresponding input couplers of thesurgical instrument. The surgical instrument includes mechanisms thatdrivingly couple the input couplers with an associated motion of thesurgical instrument (e.g., main shaft rotation, end effector pitch, endeffector yaw, end effector jaw clamping). In many existing minimallyinvasive telesurgical robotic systems, there are four drive couplersintegrated in with each of the mounting fixtures (e.g., one drivecoupler to actuate main shaft rotation, one drive coupler to actuate endeffector pitch, one drive coupler to actuate end effector yaw, and onedrive coupler to actuate end effector jaw articulation).

A problem arises, however, when it is desired to employ a surgical robothaving a number of output couplers per mounting fixture (e.g., four) tomanipulate a surgical instrument having more than that number offunctions (e.g., five such as main shaft rotation, end effector pitch,end effector yaw, end effector jaw clamping, and tissue cutting).

Thus, there is believed to be a need for surgical assemblies and relatedmethods that employ a single input drive for two end effector functions(e.g., two different mechanisms).

BRIEF SUMMARY

Methods for treating tissue, and surgical assemblies and related methodsare disclosed in which a single input is used to sequentially articulatetwo members. The single input is moved through a range of motion. Duringa first portion of the range of motion, the input link is drivinglycoupled with a first articulated member (e.g., a jaw operable to griptissue). Then, during a second portion of the range of motion, the inputlink is drivingly coupled with a second articulated member (e.g., acutter operable to cut tissue). Accordingly, a robotic arm having anumber of output couplers per mounting fixture (e.g., four) can be usedto manipulate a surgical instrument having more than that number offunctions (e.g., five such as main shaft rotation, end effector pitch,end effector yaw, end effector jaw clamping, and tissue cutting).

Thus, in a first aspect, a surgical assembly is provided. The surgicalassembly includes an end effector, a base supporting the end effector,an input link movable relative to the base through a range of motionbetween a first configuration and a second configuration, and anactuation mechanism. The end effector includes a first articulatedmember and a second articulated member. The actuation mechanismdrivingly couples the input link to the first articulated member withina first portion of the range of motion and drivingly coupling the inputlink with the second articulated member within a second portion of therange of motion so that a movement of the input link from the firstconfiguration to the second configuration articulates the firstarticulated member and then articulates the second articulated member.

In many embodiments of the surgical assembly, the first and secondarticulated members are configured to manipulate tissue. For example,the first articulated member can have a first articulation rangeconfigured for a first desired manipulation of tissue. And the secondarticulated member can have a second articulation range configured for asecond desired manipulation of tissue. The movement of the input linkcan actuate the first articulated member throughout the firstarticulation range primarily within the first portion of the range ofmotion, and can actuate the second articulated member throughout thesecond articulation range within the second portion of the range ofmotion. The first and second portions of the range of motion areseparate so as to facilitate independently effecting the first andsecond desired manipulations of tissue. In many embodiments, the firstarticulated member includes a jaw operable to grip tissue and the secondarticulated member includes a cutter operable to cut tissue.

In many embodiments of the surgical assembly, the input link isdrivingly coupled with the jaw through a spring that deflects during thesecond portion of the range of motion to at least partially decouplemotion of the jaw from motion of the input link during the secondportion of the range of motion. For example, the spring can inhibitrelative movement between the input link and a first output link duringthe first portion of the range of motion, the first output link beingdrivingly coupled with the jaw. The spring can deflect to allow relativemotion between the input link and the first output link during thesecond portion of the range of motion. And the input link can drive asecond output link during the second portion of the range of motion, thesecond output link being drivingly coupled with the cutter.

Any suitable type of spring can be used. For example, the spring caninclude an extension spring. And linear motion of the input linkrelative to the base can be used to induce articulation of the jaw andthe cutter. As another example, the spring can include a torsion spring.And rotation of the input link relative to the base can be used toinduce articulation of the jaw and the cutter.

The actuation mechanism can include a cam surface drivingly coupled withthe input link and shaped to inhibit driving of the cutter during thefirst portion of the range of motion and drive the cutter during thesecond portion of the range of motion. For example, a rotation of theinput link relative to the base can be used to induce a rotation of thecam surface relative to the base. The actuation mechanism can include amember with a slot that defines the cam surface and a follower thatengages the slot and is drivingly coupled with the cutter by a linkage.The slotted member can be mounted for rotation relative to the baseabout an axis of rotation. The slot can include a first segment having acenterline with a constant radius relative to the axis of rotation and asecond segment having a centerline with a varying radius relative to theaxis of rotation. The follower can engage the first segment during thefirst portion of the range of motion and can engage the second segmentduring the second portion of the range of motion.

The actuation mechanism can include two separate cam surfaces that aredrivingly coupled with the input link. For example, a first cam surfacecan be drivingly coupled with the input link and shaped to actuate thefirst articulated member. And a second cam surface can also be coupledwith the input link and shaped to actuate the second articulated member.The first cam surface can be part of a first slotted member that isdrivingly coupled with the input link. And the second cam surface can bepart of a second slotted member that is drivingly coupled with the inputlink. The first and second articulated members can be drivingly coupledwith respective followers that engage the first and second cam surfaces,respectively.

The actuation mechanism can include one or more cam surfaces such asdisclosed herein and the input link can be drivingly coupled with thejaw through a spring that deflects to at least partially decouple motionof the jaw from motion of the input link such as disclosed herein. Sucha combined embodiment can be used to provide flexibility with regard tothe amount of jaw articulation that occurs prior to the articulation ofthe cutter, such as when items of different sizes are gripped by thejaw.

In another aspect, a method of treating tissue is provided. The methodincludes moving an input link relative to a base through a range ofmotion, articulating a jaw within a first portion of the range of motionso as to grasp the tissue, and articulating a cutter within a secondportion of the range of motion so as to cut the tissue, the articulatingof the jaw and the cutter being primarily independent.

In many embodiments of the method of treating tissue, the articulationof the jaw includes inhibiting relative movement between the input linkand an output link during the first portion of the range of motion witha spring coupled with the input link and the output link, the outputlink being drivingly coupled with the jaw. The articulation of thecutter can include deflecting the spring to at least partially decouplemotion of the output link from the input link during the second portionof the range of motion.

Any suitable type of spring can be used. For example, the spring caninclude an extension spring. And the method can include translating theinput link relative to the base to induce the articulation of the jawand the cutter. As another example, the spring can include a torsionspring. And the method can include rotating the input link relative tothe base to induce the articulation of the jaw and the cutter.

In many embodiments, the method of treating tissue includes rotating amember having a slot in response to rotation of the input link andengaging the slot with a follower that is drivingly coupled with thecutter. The method of treating tissue can include rotating the slottedmember about an axis of rotation relative to the base. The slot caninclude a first segment having a centerline with a constant radiusrelative to the axis of rotation and a second segment having acenterline with a varying radius relative to the axis of rotation. Themethod of treating tissue can include engaging the first segment withthe follower during the first portion of the range of motion andengaging the second segment with the follower during the second portionof the range of motion.

The method of treating tissue can include both rotating a member havinga slot in response to rotation of the input link and engaging the slotwith a follower that is drivingly coupled with the cutter such asdisclosed herein, and inhibiting relative movement between the inputlink and an output link with a spring coupled with the input link andthe output link, the output link being drivingly coupled with the jaw,such as disclosed herein. And the method can include deflecting thespring to at least partially decouple motion of the output link from theinput link such as disclosed herein. Such a combined embodiment can beused to provide flexibility with regard to the amount of jawarticulation that occurs prior to the articulation of the cutter, suchas when items of different sizes are gripped by the jaw.

In another aspect, a method is provided for articulating an end effectorof a surgical assembly. The method includes moving an input linkrelative to a base through a range of motion, articulating a firstmember of the end effector within a first portion of the range ofmotion, and articulating a second member of the end effector within asecond portion of the range of motion, the first and second membersbeing different and the articulating of the first and second membersbeing primarily independent.

In many embodiments of the method for articulating an end effector of asurgical assembly, the first member includes a jaw configured to grip atissue and the second member includes a cutter configured to cut thetissue. In many embodiments of the method for articulating an endeffector of a surgical assembly, the jaw has a first articulation rangeconfigured to grip a tissue and the cutter has a second articulationrange configured to cut the tissue. Movement of the input link actuatesthe jaw throughout the first articulation range primarily within thefirst portion of the range of motion, and actuates the cutter throughoutthe second articulation range within the second portion of the range ofmotion. The first and second portions of the range of motion areseparate so as to facilitate independently gripping the tissue andcutting the gripped tissue.

For a fuller understanding of the nature and advantages of the presentinvention, reference should be made to the ensuing detailed descriptionand accompanying drawings. Other aspects, objects and advantages of theinvention will be apparent from the drawings and detailed descriptionthat follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a minimally invasive robotic surgery systembeing used to perform a surgery, in accordance with many embodiments.

FIG. 2 is a perspective view of a surgeon's control console for arobotic surgery system, in accordance with many embodiments.

FIG. 3 is a perspective view of a robotic surgery system electronicscart, in accordance with many embodiments.

FIG. 4 diagrammatically illustrates a robotic surgery system, inaccordance with many embodiments.

FIG. 5A is a front view of a patient side cart (surgical robot) of arobotic surgery system, in accordance with many embodiments.

FIG. 5B is a front view of a robotic surgery tool, in accordance withmany embodiments.

FIG. 6A is a perspective view of a robotic surgery tool that includes anend effector having opposing clamping jaws, in accordance with manyembodiments.

FIG. 6B is a close-up perspective view of the end effector of FIG. 6A.

FIG. 7 is an exploded perspective view of the end effector of FIG. 6A,illustrating a mechanism used to convert rotary motion of a drive shaftinto articulation of the opposing clamping jaws.

FIGS. 8A and 8B are perspective views of an end effector having opposingclamping jaws and a mechanism used to convert rotary motion of a driveshaft into articulation of the opposing clamping jaws, in accordancewith many embodiments.

FIG. 9 is a simplified schematic illustrating an actuation mechanism inwhich a single input link is used to sequentially articulate twomembers, in accordance with many embodiments.

FIG. 10 is a simplified schematic illustrating a mechanism that actuatesa cutter during a second portion of a range of rotational motion of aninput link, in accordance with many embodiments.

FIG. 11 is a perspective view of a proximal chassis of a surgicalinstrument that includes a mechanism that actuations a cutter during asecond portion of a range of rotational motion of an input link, inaccordance with many embodiments.

FIG. 12 is a perspective view of a proximal chassis of another surgicalinstrument that includes a mechanism that actuations a cutter during asecond portion of a range of rotational motion of an input link, inaccordance with many embodiments.

FIG. 13A schematically illustrates an actuation mechanism having twoseparate slotted members rotationally coupled with a common input linkto drive two separate output links, in accordance with many embodiments.

FIG. 13B schematically illustrates a first slotted member of theactuation mechanism of FIG. 13A.

FIG. 13C schematically illustrates a second slotted member of theactuation mechanism of FIG. 13A.

FIG. 14 illustrates acts of a method for articulating two separatemembers of an end effector by using a single input, in accordance withmany embodiments.

FIG. 15 illustrates acts of a method for treating tissue, in accordancewith many embodiments.

DETAILED DESCRIPTION

In the following description, various embodiments of the presentinvention will be described. For purposes of explanation, specificconfigurations and details are set forth in order to provide a thoroughunderstanding of the embodiments. However, it will also be apparent toone skilled in the art that the present invention may be practicedwithout the specific details. Furthermore, well-known features may beomitted or simplified in order not to obscure the embodiment beingdescribed.

Minimally Invasive Robotic Surgery

Referring now to the drawings, in which like reference numeralsrepresent like parts throughout the several views, FIG. 1 is a plan viewillustration of a Minimally Invasive Robotic Surgical (MIRS) system 10,typically used for performing a minimally invasive diagnostic orsurgical procedure on a Patient 12 who is lying down on an Operatingtable 14. The system can include a Surgeon's Console 16 for use by aSurgeon 18 during the procedure. One or more Assistants 20 may alsoparticipate in the procedure. The MIRS system 10 can further include aPatient Side Cart 22 (surgical robot) and an Electronics Cart 24. ThePatient Side Cart 22 can manipulate at least one removably coupled toolassembly 26 (hereinafter simply referred to as a “tool”) through aminimally invasive incision in the body of the Patient 12 while theSurgeon 18 views the surgical site through the Console 16. An image ofthe surgical site can be obtained by an endoscope 28, such as astereoscopic endoscope, which can be manipulated by the Patient SideCart 22 so as to orient the endoscope 28. The Electronics Cart 24 can beused to process the images of the surgical site for subsequent displayto the Surgeon 18 through the Surgeon's Console 16. The number ofsurgical tools 26 used at one time will generally depend on thediagnostic or surgical procedure and the space constraints within theoperating room among other factors. If it is necessary to change one ormore of the tools 26 being used during a procedure, an Assistant 20 mayremove the tool 26 from the Patient Side Cart 22, and replace it withanother tool 26 from a tray 30 in the operating room.

FIG. 2 is a perspective view of the Surgeon's Console 16. The Surgeon'sConsole 16 includes a left eye display 32 and a right eye display 34 forpresenting the Surgeon 18 with a coordinated stereo view of the surgicalsite that enables depth perception. The Console 16 further includes oneor more input control devices 36, which in turn cause the Patient SideCart 22 (shown in FIG. 1) to manipulate one or more tools. The inputcontrol devices 36 can provide the same degrees of freedom as theirassociated tools 26 (shown in FIG. 1) so as to provide the Surgeon withtelepresence, or the perception that the input control devices 36 areintegral with the tools 26 so that the Surgeon has a strong sense ofdirectly controlling the tools 26. To this end, position, force, andtactile feedback sensors (not shown) may be employed to transmitposition, force, and tactile sensations from the tools 26 back to theSurgeon's hands through the input control devices 36.

The Surgeon's Console 16 is usually located in the same room as thepatient so that the Surgeon may directly monitor the procedure, bephysically present if necessary, and speak to an Assistant directlyrather than over the telephone or other communication medium. However,the Surgeon can be located in a different room, a completely differentbuilding, or other remote location from the Patient allowing for remotesurgical procedures.

FIG. 3 is a perspective view of the Electronics Cart 24. The ElectronicsCart 24 can be coupled with the endoscope 28 and can include a processorto process captured images for subsequent display, such as to a Surgeonon the Surgeon's Console, or on another suitable display located locallyand/or remotely. For example, where a stereoscopic endoscope is used,the Electronics Cart 24 can process the captured images so as to presentthe Surgeon with coordinated stereo images of the surgical site. Suchcoordination can include alignment between the opposing images and caninclude adjusting the stereo working distance of the stereoscopicendoscope. As another example, image processing can include the use ofpreviously determined camera calibration parameters so as to compensatefor imaging errors of the image capture device, such as opticalaberrations.

FIG. 4 diagrammatically illustrates a robotic surgery system 50 (such asMIRS system 10 of FIG. 1). As discussed above, a Surgeon's Console 52(such as Surgeon's Console 16 in FIG. 1) can be used by a Surgeon tocontrol a Patient Side Cart (Surgical Robot) 54 (such as Patient SideCart 22 in FIG. 1) during a minimally invasive procedure. The PatientSide Cart 54 can use an imaging device, such as a stereoscopicendoscope, to capture images of the procedure site and output thecaptured images to an Electronics Cart 56 (such as the Electronics Cart24 in FIG. 1). As discussed above, the Electronics Cart 56 can processthe captured images in a variety of ways prior to any subsequentdisplay. For example, the Electronics Cart 56 can overlay the capturedimages with a virtual control interface prior to displaying the combinedimages to the Surgeon via the Surgeon's Console 52. The Patient SideCart 54 can output the captured images for processing outside theElectronics Cart 56. For example, the Patient Side Cart 54 can outputthe captured images to a processor 58, which can be used to process thecaptured images. The images can also be processed by a combination theElectronics Cart 56 and the processor 58, which can be coupled togetherso as to process the captured images jointly, sequentially, and/orcombinations thereof. One or more separate displays 60 can also becoupled with the processor 58 and/or the Electronics Cart 56 for localand/or remote display of images, such as images of the procedure site,or other related images.

FIGS. 5A and 5B show a Patient Side Cart 22 and a surgical tool 62,respectively. The surgical tool 62 is an example of the surgical tools26. The Patient Side Cart 22 shown provides for the manipulation ofthree surgical tools 26 and an imaging device 28, such as a stereoscopicendoscope used for the capture of images of the site of the procedure.Manipulation is provided by robotic mechanisms having a number ofrobotic joints. The imaging device 28 and the surgical tools 26 can bepositioned and manipulated through incisions in the patient so that akinematic remote center is maintained at the incision so as to minimizethe size of the incision. Images of the surgical site can include imagesof the distal ends of the surgical tools 26 when they are positionedwithin the field-of-view of the imaging device 28.

Tissue Gripping End Effectors

FIG. 6A shows a surgical tool 70 that includes a proximal chassis 72, aninstrument shaft 74, and a distal end effector 76 having a jaw 78 thatcan be articulated to grip a patient tissue. The proximal chassisincludes an input coupler that is configured to interface with and bedriven by an output coupler of the Patient Side Cart 22. The inputcoupler is drivingly coupled with an input link of a spring assembly 80.The spring assembly 80 is mounted to a frame 82 of the proximal chassis72 and includes an output link that is drivingly coupled with a driveshaft that is disposed within the instrument shaft 74. The drive shaftis drivingly coupled with the jaw 78. FIG. 6B provides a close-up viewof the jaw 78 of the end effector 76.

FIG. 7 is an exploded perspective view of the end effector 76 of FIG.6A, illustrating a clamping mechanism used to convert rotary motion of adrive shaft 84 into articulation of opposing clamping jaws of the endeffector 76. The end effector includes an upper jaw 86, a lower jaw 88,a frame 90, a pin 92 for pivotally mounting the upper jaw 86 and thelower jaw 88 to the frame 90, and a lead screw mechanism 94 that isdrivingly coupled with the drive shaft 84. The lead screw mechanism 94includes a lead screw 96 and a mating translating nut 98 that isadvanced and retracted along a slot 100 in the frame 90 via rotation ofthe lead screw 96. The translating nut 98 includes oppositely extendingprotrusions that interface with a slot 102 in the upper jaw 86 and witha slot 104 in the lower jaw 88, thereby causing articulation of theupper jaw 86 and the lower jaw 88 about the pin 92 when the translatingnut 98 is advanced or retracted along the slot 100.

The end effector 76 further includes a cutter 106 operable to cut agripped tissue. The cutter 106 is coupled to a drive member 108. Thecutter 106 is advanced distally by a corresponding distal advancement ofthe drive member 108 and is retracted proximally by a correspondingproximal retraction of the drive member 108. Each of the upper jaw 86and the lower jaw 88 include a slot 110 that can accommodate a portionof the cutter 106 throughout its range of travel, thereby serving torestrain and guide the cutter 106 throughout its range of motion. Inmany embodiments, the drive member 108 extends between the cutter 106and the proximal chassis 72 and is drivingly coupled with an actuationmechanism disposed in the proximal chassis. The actuation mechanism inthe proximal chassis can push the drive member 108 distally to advancethe cutter 106 distally to cut a gripped tissue. The actuation mechanismcan pull the drive member 108 proximally to return the cutter 106 to aretracted starting position.

FIG. 8A and FIG. 8B illustrate the operation of a clamping mechanismsimilar to the clamping mechanism of FIG. 7. Rotating the drive shaft 84in the direction shown causes a translating nut 98 to advance distallytoward the pivot pin 92 by which the lower jaw 88 and the upper jaw 86are pivotally mounted to the frame 90 of an end effector. As illustratedin FIG. 8B, a protrusion of the translating nut 98 engages the slot 102in the upper jaw 86. Distal advancement of the translating nut 98 towardthe pivot pin 92 causes the upper jaw to rotate in the direction shown,and causes the lower jaw 88 to rotate in the opposite direction, therebyopening the jaw. Similarly, proximal advancement of the translating nut98 away from the pivot pin 92 cause the jaw to close. Accordingly, thejaw can be articulated to grip a patient tissue.

The end effector 76 can be used to sequentially grip a tissue and thencut the gripped tissue. For example, with the cutter 106 positioned atthe retracted starting position (i.e., positioned proximal to thegripping surfaces of the jaw), the jaw 78 can be articulated to grip atissue. Then, proximal advancement of the cutter 106 along the slots 110can be accomplished to cut the gripped tissue.

Single Drive Input for Two End Effector Mechanisms

FIG. 9 schematically illustrates an actuation mechanism 120 in which asingle input link 122 is used to sequentially articulate two members, inaccordance with many embodiments. The actuation mechanism 120 includesthe input link 122, a first output link 124 that is drivingly coupledwith the jaw 78 operable to grip tissue, a second output link 126 thatis drivingly coupled with the cutter 106 operable to cut the grippedtissue, and a preloaded spring 128 coupled between the input link 122and the first output link 124. An input coupler 130 (also known as aninput “dog”) is drivingly coupled with the input link 122.

The input link 122 is driven by the input coupler 130 through a range ofmotion (e.g., from left to right in FIG. 9). During a first portion ofthe range of motion, the preloaded spring 128 pulls the first outputlink 124 to the right, and thereby maintaining contact between the inputlink 122 and the first output link 124. At some point during the rangeof motion, the jaw begins to either grip tissue or reaches a closedconfiguration, thereby causing the actuation force transferred to thejaw by the first output link 124 to increase. Once the actuation forcetransferred to the jaw by the first output link 124 exceeds apredetermined level corresponding to the preload force level in thepreloaded spring 128, further movement of the input link 122 to theright causes the preloaded spring 128 to extend, thereby allowing theinput link 122 and the first output link 124 to separate. Furthermovement of the input link 122 to the right causes further extension ofthe preloaded spring 128, thereby causing increased separation betweenthe input link 122 and the first output link 124.

During a second portion of the range of motion (i.e., after the firstportion of the range of motion), the input link 122 comes into contactwith the second output link 126, which is drivingly coupled with thecutter 106. Further movement of the input link 122 to the right drivesthe second output link 126 to the right, thereby causing actuation ofthe cutter 106. During the second portion of the range of motion,extension of the preloaded spring 128 provides for an increasing amountof separation between a substantially non-moving first output link 124and the input link 122 as the input link 122 drives the second outputlink 126 to the right. The second output link 126 and/or the cutter 106can be attached to a return mechanism (e.g., a spring) that returns thesecond output link 126 and/or the cutter 106 to the retracted startingposition in the absence of contact between the input link 122 and thesecond output link 126 (e.g., during the first portion of the range ofmotion of the input link).

While the actuation mechanism 120 is shown and described with respect tothe preloaded spring 128 being an extension spring, any suitable springcan be used. For example, the preloaded spring 128 can be a torsionspring and rotational movement of the input coupler 130 can inducerotational movement of the input link 122, rotational driving of thefirst output link 124, rotational deflection of the preloaded torsionspring 128, and rotational driving of the second output link 126.

FIG. 10 schematically illustrates another actuation mechanism 140 inwhich a single input link 142 is used to sequentially articulate twomembers, in accordance with many embodiments. The actuation mechanism140 includes the input link 142 mounted for rotation relative to a basearound a rotation axis 144, a first toggle link 146 mounted for rotationrelative to the base around a first pivot point 148, a connection link150, a second toggle link 152 mounted for rotation relative to the basearound a second pivot point 154, and a drive link 156. The input link142 includes a slot 158. The first toggle link 146 includes a follower160 that engages the slot 158. The first toggle link 146 is coupled withthe connection link 150 via a first connection pin 162. The connectionlink 150 is coupled with the second toggle link 152 via a secondconnection pin 164. The second toggle link 152 is coupled with the drivelink 156 via a third connection pin 166.

The input link 142 and the output link 156 are used to sequentiallyarticulate the two members. The input link 142 is drivingly coupled withan actuation mechanism that articulates a first of the two members. Forexample, the input link 142 can be drivingly coupled with an actuationmechanism that articulates an end effector jaw that is operable to gripa tissue. Motion of the drive link 156 causes articulation of a secondof the two members. For example, motion of the drive link 156 can beused to articulate a cutter operable to cut a tissue, for example, atissue gripped by an end effector jaw.

The actuation mechanism 140 is configured to produce substantially nomovement of the drive link 156 during a first portion of a range ofmotion of the input link 142 and to produce substantially axial movementof the drive link 156 during a second portion of the range of motion ofthe input link 142. The input link 142 includes the slot 158 and thefirst toggle link 146 includes the follower 160 that engages the slot158. The slot 158 includes a first segment 168 having a centerline witha substantially constant radius relative to the rotation axis 144 and asecond segment 170 having a centerline with a varying radius relative tothe rotation axis 144. The follower 160 engages the slot 158 along thefirst segment 168 during the first portion of the range of motion of theinput link 142 and engages the slot 158 along the second segment 170during the second portion of the range of motion of the input link 142.During the first portion of the range of motion of the input link 142,the substantially constant radius of the first segment 168 of the slot158 produces no movement of the first toggle link 146, thereby producingno movement of the drive link 156. During the second portion of therange of motion of the input link 142, the varying radius of the secondsegment 170 of the slot 158 produces clockwise movement of the firsttoggle link 146 about the first pivot point 148, which produces acorresponding clockwise motion of the second toggle link 152 about thesecond pivot point 154, which produces an upward substantially axialmovement of the drive link 156. By reversing the motion of the inputlink 142, an opposite downward substantially axial movement of drivelink 156 occurs during the second portion of the range of motion,thereby returning the drive link 156 to its starting position.

In many embodiments, the input link 142 is coupled to the first of thetwo members through a mechanism that allows the first of the two membersto be substantially stationary during the second portion of the range ofmotion of the input link 142. For example, when the input link 142 isdrivingly coupled with an actuation mechanism that articulates a jawoperable to grip a tissue, a spring loaded mechanism similar to theactuation mechanism 120 described above can be used to provide forrelative movement during the second portion of the range of motion ofthe input link 142 between the input link 142 and an output link that isdrivingly coupled with the actuation mechanism that articulates a jawoperable to grip a tissue. Additional approaches for coupling the inputlink 142 to the first of the two members so as to allow for relativemovement between the input link 142 and the first of the two membersduring the second portion of the range of motion of the input link 142are described in U.S. Provisional Application No. 61/491,804, entitled“Grip Force Control in a Robotic Surgical Instrument,” filed on May 31,2011, the full disclosure of which is incorporated herein by reference.

FIG. 11 shows a proximal chassis 170 of a surgical instrument thatincludes an actuation mechanism 172 in which a single input link 174 isused to sequentially articulate two members, in accordance with manyembodiments. The actuation mechanism 122 includes the input link 174mounted to a base 176 for rotation about a rotation axis 178, a firstlink 180 mounted to the base to translate in one direction relative tothe base, a toggle link 182 mounted for rotation relative to the basearound a pivot point 184, and a drive link 186. The input link 174includes a slot 188 and the first link 180 includes a follower 190 thatengages the slot 188. The slot 188 includes a first segment having acenterline with a substantially constant radius relative to the rotationaxis 178 and a second segment having a centerline with a varying radiusrelative to the rotation axis 178. The follower 190 engages the slot 188along the first segment during the first portion of the range of motionof the input link 174 and engages the slot 188 along the second segmentduring the second portion of the range of motion of the input link 174.During the first portion of the range of motion of the input link 174,the substantially constant radius of the first segment of the slot 188produces no movement of the first link 180, thereby producing nomovement of the drive link 186. During the second portion of the rangeof motion of the input link 174, the varying radius of the secondsegment of the slot 188 produces axial movement of the first link 180,which produces a clockwise motion of the toggle link 182 about the pivotpoint 184, which produces a distal substantially axial movement of thedrive link 186. By reversing the motion of the input link 174, anopposite proximal substantially axial movement of drive link 186 occursduring the second portion of the range of motion, thereby returning thedrive link 186 to its starting position.

As described above with regard to the input link 142 of the actuationmechanism 140, the input link 174 of the actuation mechanism 172 can becoupled to the first of the two members through a mechanism that allowsthe first of the two members to be substantially stationary during thesecond portion of the range of motion of the input link 174 usingsimilar approaches.

FIG. 12 shows a proximal chassis 191 of another surgical instrument thatincludes an actuation mechanism 192 in which a single input link 194 isused to sequentially articulate two members, in accordance with manyembodiments. The actuation mechanism 192 is configured and operatessimilar to the actuation mechanism 172 discussed above. The actuationmechanism 192 does include some addition features. These additionalfeatures include a first link 196 that includes a double shear clevis198 having a guide slot 200. The double shear clevis 198 provides doubleshear support of the follower that engages the slot in the input link194. The guide slot 200 serves to restrain the follower end of the firstlink 196 against any movement of the follower end transverse to thedirection in which the first link is mounted to translate relative tothe base. An end restraint 202 is also provided adjacent to theconnection between the first link 196 and the toggle link 182 torestrain the end of the first link against any movement transverse tothe direction in which the first link is mounted to translate relativeto the base.

FIG. 13A, FIG. 13B, and FIG. 13C schematically illustrate an actuationmechanism 210 in which a single input link is used to sequentiallyarticulate two output links, in accordance with many embodiments. Theactuation mechanism 210 includes an input link 212, a first output link214, a second output link 216, a first slotted member 218, and a secondslotted member 220.

The input link 212 is mounted for rotation relative to a base 222 (e.g.,a proximal chassis of a surgical instrument as described herein). Theinput link 212 is attached to an input coupler 224 that is configured tointerface with and be rotationally driven by an output coupler of thePatient Side Cart 22. Each of the first and second slotted members 218,220 is attached to the input link 212 to rotate therewith.

The first output link 214 is constrained to translate along a directionof motion and includes a follower 226 that engages a slot 228 in thefirst slotted member 218. FIG. 13B illustrates the slot 228, whichincludes a first segment 230 having a varying radius relative to arotational center 232 of the first slotted member 218, and a secondsegment 233 having a substantially constant radius relative to therotational center 232. In many embodiments, the first output link 214 isconstrained to translate along a line that intersects or passesrelatively close to the rotational center 232 so as to substantiallyalign the force applied to the first output link 214 by the firstslotted member 218 with the direction of motion of the first output link214. Rotation of the first slotted member 218 by the input link 212causes translation of the first output link 214 along its direction ofmotion when the follower 226 is engaged by the first segment 230 of theslot 228. This translation of the first output link 214 is caused by thechange in radial position between the follower 226 and the rotationalcenter 232 when the follower 226 is engaged by the first segment 230.And rotation of the first slotted member 218 by the input link 212produces substantially zero translation of the first output link 214along its direction of motion when the follower 226 is engaged by thesecond segment 233 of the slot 228. The substantially zero translationof the first output link 214 results from the constant radial positionbetween the follower 226 and the rotational center 232 when the follower226 is engaged by the second segment 233.

The second output link 216 is constrained to translate along a directionof motion and includes a follower 234 that engages a slot 236 in thesecond slotted member 220. FIG. 13C illustrates the slot 236, whichincludes a first segment 238 having a substantially constant radiusrelative to a rotational center 240 of the second slotted member 220,and a second segment 242 having a varying radius relative to therotational center 240. In many embodiments, the second output link 216is constrained to translate along a line that intersects or passesrelatively close to the rotational center 240 so as to substantiallyalign the force applied to the second output link 216 by the secondslotted member 220 with the direction of motion of the second outputlink 216. Rotation of the second slotted member 220 by the input link212 produces substantially zero translation of the second output link216 along its direction of motion when the follower 234 is engaged bythe first segment 238 of the slot 236. The substantially zerotranslation of the second output link 216 results from the constantradial position between the follower 234 and the rotational center 240when the follower 234 is engaged by the first segment 238. And rotationof the second slotted member 220 by the input link 212 causestranslation of the second output link 216 along its direction of motionwhen the follower 234 is engaged by the second segment 242 of the slot236. This translation of the second output link 216 is caused by thechange in radial position between the follower 234 and the rotationalcenter 240 when the follower 234 is engaged by the second segment 242.

In operation, the first output link 214 translates and the second outputlink 216 remains stationary during a first portion of a range ofrotation of the input link 212, and the first output link 214 remainsstationary and the second output link 216 translates during a secondportion of a range of rotation of the input link 212. During the firstportion of the range of rotation of the input link 212, the first outputlink follower 226 is engaged by the first segment 230 of the slot 228 inthe first slotted member 218 and the second output link follower 234 isengaged by the first segment 238 of the slot 236 in the second slottedmember 220. During the second portion of the range of rotation of theinput link 212, the first output link follower 226 is engaged by thesecond segment 233 of the slot 228 in the first slotted member 218 andthe second output link follower 234 is engaged by the second segment 242of the slot 236 in the second slotted member 220.

The actuation mechanism 210 can be used to articulate an end effectorjaw operable to grip tissue, such as the end effector jaw 78 describedherein, and an additional end effector mechanism, such as the cutter 106described herein. For example, the first output link 214 can bedrivingly coupled with an end effector jaw operable to grip a patienttissue and the second output link 216 can be drivingly coupled with acutter operable to cut the gripped patient tissue. In such anarrangement, rotation of the input link 212 through the first range ofrotation causes articulation of the end effector jaw to grip a patienttissue along with no substantial movement of the cutter. Then, furtherrotation of the input link 212 through the second range of rotationcauses no further articulation of the end effector jaw along witharticulation of the cutter to cut the gripped tissue. Other end effectormechanisms (e.g., a mechanism for deploying staples) can also bearticulated by the actuation mechanism 210. For example, the firstoutput link 214 can be drivingly coupled with a staple deployingmechanism and the second output link 216 can be drivingly coupled with acutter mechanism, thereby providing for a sequential deployment ofstaples followed by actuation of the cutter to cut the stapled tissue.

In many embodiments, the first output link 214 and/or the second outputlink 216 is coupled to its respective end effector mechanism by a springloaded mechanism similar to the actuation mechanism 120 describe hereinso as to control the amount of force transferred to the end effectormechanism by providing for relative movement between the respectiveoutput link and the respective end effector mechanism. Additionalapproaches for coupling the output links 214, 216 to a respective endeffector mechanism are described in U.S. Provisional Application No.61/491,804, entitled “Grip Force Control in a Robotic SurgicalInstrument,” filed on May 31, 2011, which has been incorporated byreference above.

Surgical Assembly Applications

The surgical assemblies and instruments disclosed herein can be employedin any suitable application. For example, the surgical assembliesdisclosed herein can be employed in other surgical instruments, manualor powered, hand-held or robotic, directly controlled or teleoperated,for open or minimally invasive (single or multi-port) procedures.Examples of such instruments include those with distal components thatreceive torque actuating inputs (e.g., for grip control functions,component orientation control functions, component position functions,etc.). Illustrative non-limiting examples include teleoperated orhand-held instruments that include stapling, cutting, tissue fusing,imaging device orientation and position control, high force grasping,biopsy, and end effector and orientation control.

Methods for Articulating Two Members with a Single Drive Input

FIG. 14 illustrates acts of a method 250 for articulating an endeffector of a surgical assembly, in accordance with many embodiments.The method 250 can be practiced, for example, with the surgicalassemblies and/or instruments disclosed herein.

The method 250 includes moving an input link relative to a base througha range of motion (act 252), articulating a first member of the endeffector within a first portion of the range of motion (act 254), andarticulating a second member of the end effector within a second portionof the range of motion (act 256). The first and second members aredifferent. And the articulation of the first member and the articulationof the second member are primarily independent.

In many embodiments, the end effector is configured to treat a tissue.For example, the articulated first member of the end effector caninclude a jaw configured to grip a tissue, and the articulated secondmember of the end effector can include a cutter configured to cut thetissue. The jaw can have a first articulation range configured to gripthe tissue and the cutter can have a second articulation rangeconfigured to cut the tissue. Movement of the input link can actuate thejaw throughout the first articulation range primarily within the firstportion of the range of motion, and can actuate the cutter throughoutthe second articulation range within the second portion of the range ofmotion. In many embodiments, the first and second portions of the rangeof motion are separate so as to facilitate independently gripping thetissue and cutting the gripped tissue.

Any other suitable combination of end effector articulated members canbe used as the first and second members. For example, the articulatedfirst member can include a mechanism for deploying staples into atissue, and the articulated second member can include a cutter forcutting the stapled tissue. As another example, the articulated firstmember can include a jaw operable to grip a tissue, and the articulatedsecond member can include a mechanism for deploying staples into thegripped tissue.

FIG. 15 illustrates acts of a method 260 of treating tissue, inaccordance with many embodiments. The method 260 can be practiced, forexample, with the surgical assemblies and/or instruments disclosedherein.

The method 260 includes moving an input link relative to a base througha range of motion (act 262), articulating a jaw within a first portionof the range of motion so as to grasp the tissue (act 264), andarticulating a cutter within a second portion of the range of motion,the articulating of the jaw and the cutter being primarily independent(act 266).

In many embodiments of the method 260, the articulation of the jawincludes inhibiting relative movement between the input link and anoutput link during the first portion of the range of motion with aspring coupled with the input link and the output link, the output linkbeing drivingly coupled with the jaw. The articulation of the cutter caninclude deflecting the spring to at least partially decouple motion ofthe output link from the input link during the second portion of therange of motion. Any suitable type of spring can be used (e.g., anextension spring, a torsion spring). Any suitable type of motion of theinput link relative to the base can be used to induce the articulationof the jaw and cutter (e.g., translation of the input link relative tothe base, rotation of the input link relative to the base).

The cutter can be articulated by using a cam surface that is drivinglycoupled with the input link and a follower that engages the cam surfaceand is drivingly coupled with the cutter. For example, the method 260can include rotating a member having a slot in response to rotation ofthe input link, and engaging the slot with a follower that is drivinglycoupled with the cutter. The slotted member can be rotated about an axisof rotation relative to the base. The slot can include a first segmenthaving a centerline with a constant radius relative to the axis ofrotation and a second segment having a centerline with a varying radiusrelative to the axis of rotation. The follower can engage the firstsegment during the first portion of the range of motion. And thefollower can engage the second segment during the second portion of therange of motion.

Two or more slotted members can be used to drive a corresponding two ormore end effector mechanisms. For example, the method 260 can includerotating a first member having a first slot in response to rotation ofthe input link, engaging the first slot with a first follower that isdrivingly coupled with the jaw, rotating a second member having a secondslot in response to rotation of the input link, and engaging the secondslot with a second follower that is drivingly coupled with the cutter.

Method Applications

The methods disclosed herein can be employed in any suitableapplication. For example, the methods disclosed herein can be employedin surgical instruments, manual or powered, hand-held or robotic,directly controlled or teleoperated, for open or minimally invasive(single or multi-port) procedures. Examples of such instruments includethose with distal components that receive actuating inputs (e.g., forgrip control functions, component orientation control functions,component position functions, etc.). Illustrative non-limiting examplesinclude teleoperated or hand-held instruments that include stapling,cutting, tissue fusing, imaging device orientation and position control,high force grasping, biopsy, and end effector and orientation control.

Other variations are within the spirit of the present invention. Thus,while the invention is susceptible to various modifications andalternative constructions, certain illustrated embodiments thereof areshown in the drawings and have been described above in detail. It shouldbe understood, however, that there is no intention to limit theinvention to the specific form or forms disclosed, but on the contrary,the intention is to cover all modifications, alternative constructions,and equivalents falling within the spirit and scope of the invention, asdefined in the appended claims.

The term “force” is to be construed as encompassing both force andtorque (especially in the context of the following claims), unlessotherwise indicated herein or clearly contradicted by context. The useof the terms “a” and “an” and “the” and similar referents in the contextof describing the invention (especially in the context of the followingclaims) are to be construed to cover both the singular and the plural,unless otherwise indicated herein or clearly contradicted by context.The terms “comprising,” “having,” “including,” and “containing” are tobe construed as open-ended terms (i.e., meaning “including, but notlimited to,”) unless otherwise noted. The term “connected” is to beconstrued as partly or wholly contained within, attached to, or joinedtogether, even if there is something intervening. Recitation of rangesof values herein are merely intended to serve as a shorthand method ofreferring individually to each separate value falling within the range,unless otherwise indicated herein, and each separate value isincorporated into the specification as if it were individually recitedherein. All methods described herein can be performed in any suitableorder unless otherwise indicated herein or otherwise clearlycontradicted by context. The use of any and all examples, or exemplarylanguage (e.g., “such as”) provided herein, is intended merely to betterilluminate embodiments of the invention and does not pose a limitationon the scope of the invention unless otherwise claimed. No language inthe specification should be construed as indicating any non-claimedelement as essential to the practice of the invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventors expect skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

What is claimed is:
 1. A medical device comprising: an input linkmovable through an input link range of motion, the input link range ofmotion comprising a first portion and a second portion; a jaw coupledwith the input link, the input link within the first portion of theinput link range of motion driving the jaw through a jaw range ofmotion; and a tissue manipulation member coupled to the input link andpositioned to manipulate a tissue gripped by the jaw, the input linkwithin the second portion of the input link range of motion driving thetissue manipulation member through a tissue manipulation member range ofmotion, and the input link within the first portion of the input linkrange of motion not driving the tissue manipulation member.
 2. Themedical device of claim 1, wherein the tissue manipulation membercomprises a cutter configured to cut the tissue gripped by the jaw. 3.The medical device of claim 1, wherein the tissue manipulation member isconfigured to deploy staples into the tissue gripped by the jaw.
 4. Themedical device of claim 1, wherein the jaw is coupled with the inputlink via a spring that deflects during the second portion of the inputlink range of motion.
 5. The medical device of claim 4, furthercomprising: an output link drivingly coupled to the jaw; wherein thespring inhibits relative movement between the input link and the outputlink during the first portion of the input link range of motion; andwherein the spring deflects to accommodate relative motion between theinput link and the output link during the second portion of the inputlink range of motion.
 6. The medical device of claim 4, wherein thespring comprises an extension spring or a torsion spring.
 7. The medicaldevice of claim 1, wherein the input link within the second portion ofthe input link range of motion does not drive the jaw.
 8. The medicaldevice of claim 1, wherein the jaw is coupled with the input link viaengagement between a first cam follower and a first cam surface shapedto drive the jaw within the first portion of the input link range ofmotion and to inhibit driving the jaw within the second portion of theinput link range of motion.
 9. The medical device of claim 1, whereinthe tissue manipulation member is coupled with the input link viaengagement between a cam follower and a cam surface shaped to inhibitdriving the tissue manipulation member within the first portion of theinput link range of motion and to drive the tissue manipulation memberwithin the second portion of the input link range of motion.
 10. Themedical device of claim 1, further comprising: a first cam assemblycoupling the jaw with the input link, the first cam assembly comprisinga first cam follower engaged with a first cam surface shaped to drivethe jaw within the first portion of the input link range of motion andto inhibit driving the jaw within the second portion of the input linkrange of motion; and a second cam assembly coupling the tissuemanipulation member with the input link, the second cam assemblycomprising a second cam follower engaged with a second cam surfaceshaped to drive the tissue manipulation member within the second portionof the input link range of motion and to inhibit driving the tissuemanipulation member within the first portion of the input link range ofmotion.
 11. A medical device comprising: an end effector comprising afirst member and a second member, the first member having a first rangeof motion, the second member having a second range of motion; a basesupporting the end effector; an input link movable through an input linkrange of motion relative to the base, the input link range of motioncomprising a first portion and a second portion not overlapping thefirst portion; means for driving the first member through the firstrange of motion via movement of the input link within the first portionof the input link range of motion; and means for driving the secondmember through the second range of motion via movement of the input linkwithin the second portion of the input link range of motion, wherein thesecond member is not driven via movement of the input link within thefirst portion of the input link range of motion.
 12. The medical deviceof claim 11, wherein: the first member comprises a jaw operable to gripa tissue; and the second member comprises a cutter operable to cut atissue gripped by the jaw.
 13. The medical device of claim 11, wherein:the first member comprises a jaw operable to grip a tissue; and thesecond member is configured to deploy staples into a tissue gripped bythe jaw.
 14. The medical device of claim 11, wherein: the first memberis configured to deploy staples into a tissue gripped by the endeffector; and the second member comprises a cutter operable to cut thetissue gripped by the end effector.
 15. The medical device of claim 11,wherein the first member is not driven via movement of the input linkwithin the second portion of the input link range of motion.
 16. Themedical device of claim 11, wherein the means for driving the firstmember prevents relative movement between the input link and the firstmember within the first portion of the input link range of motion andaccommodates relative motion between the input link and the first memberwithin the second portion of the input link range of motion.
 17. Themedical device of claim 11, wherein the means for driving the firstmember employs engagement between a cam follower and a cam surfaceshaped to drive the first member within the first portion of the inputlink range of motion and to inhibit driving the first member within thesecond portion of the input link range of motion.
 18. The medical deviceof claim 17, wherein the means for driving the second member employsengagement between a second cam follower and a second cam surface shapedto inhibit articulation of the second member within the first portion ofthe input link range of motion and to drive the second member within thesecond portion of the input link range of motion.
 19. The medical deviceof claim 11, wherein the means for driving the second member employsengagement between a cam follower and a cam surface shaped to inhibitdriving the second member within the first portion of the input linkrange of motion and to drive the second member within the second portionof the input link range of motion.
 20. A medical device comprising: anend effector comprising a first member and a second member, the firstmember having a first range of motion, the second member having a secondrange of motion; a base supporting the end effector; an input linkmovable through an input link range of motion relative to the base, theinput link range of motion comprising a first portion and a secondportion not overlapping the first portion; and means for driving thefirst member through the first range of motion via movement of the inputlink within the first portion of the input link range of motion withoutdriving the second member via movement of the input link within thefirst portion of the input link range of motion, and for driving thesecond member through the second range of motion via movement of theinput link within the second portion of the input link range of motionwithout driving the first member via movement of the input link withinthe second portion of the input link range of motion.